Peer-to-Peer (P2P) computing is a mainstream application model in the Internet. Existing P2P systems do not well protect their users from selfish peers or malicious adversaries. In this book, the author presents his recent research results in anonymous and trustworthy computing to meet the demands of protecting privacy, guaranteeing fairness, enabling trust, and supporting reliability in P2P systems. The book also provides effective privacy-preserving solutions for other pervasive applications, e.g., the RFID system.